Existing construction should be left undisturbed unless there is evidence of a problem. The notable exception to this practice is when we have commissioned special studies to understand the conditions of our buildings. Even in these cases we have attempted to inspect hard to reach areas with a “borescope” that leaves only a 5/8 inch hole to patch. When we do open walls and ceilings every effort is made to limit the work to the relatively easy to replace, repair and renew sheetrock, taking care to avoid disturbing existing moldings, floor finishes, subflooring, fixtures, cabinets and special finishes. Work done in the floor-ceiling cavities is done from below except where an attic permits access from above. (Bob Cowherd)